Microparticles in a silicon film created using mist-jet technology to expand the absorption wavelength

• The technique of forming the amorphous silicon film containing silicon microparticles is presented.
• The photoconductivity of the n-type silicon microparticle-containing film on the quartz substrate was increased by 1.9-fold and 4.5-fold compared with the photoconductivity of the film without microparticles in white light and in LPF, respectively.
• The silicon microparticle-containing film increased the photogenerated carrier through the optical absorption inside the silicon microparticles.

This paper presents a unique functional silicon microparticle-containing film created using a technique that combines a mist-jet ejection of crystalline silicon microparticles with the plasma-enhanced chemical vapor deposition (PE-CVD) of hydrogenated amorphous silicon. Submicron-sized crystalline silicon microparticles were ejected onto the substrate using mist-jet technology. The substrate was placed in a vacuum chamber, and a native silicon dioxide layer of microparticles was reduced using hydrogen plasma. Then, a 500-nm amorphous silicon film was deposited in the same vacuum chamber. The photocurrent of the silicon microparticle-containing films was increased by 1.9-fold compared with the photocurrent of the film without microparticles. The photocurrent increased 4.5-fold in the long wavelength with weak absorption of the amorphous silicon. Moreover, a photodiode was created to apply the film. The film was formed on a p-type silicon substrate. The photocurrent of the n-type silicon microparticle-containing film was proportional to the illuminance in the photodiode mode and increased by 1.4-fold compared with the film without microparticles. These results demonstrate that the silicon microparticle-containing film expands the absorption wavelength of amorphous silicon.